We propose a Phase I study of a topical cream containing escalating doses of sodium nitrite, a local donor of NO when in the presence of heme, as a novel approach to the therapy for chronic leg ulcers in hemolytic disorders. The primary objectives are to evaluate topical sodium nitrite cream s safety and tolerability in patients with sickle cell disease or other hemolytic disorders and chronic leg ulcers and to determine the optimal concentration of the study drug that is tolerated. Subjects will be treated at the Clinical Center for 4 weeks.